Art of waterproofing fibrous materials.



. L. Brevoort Nos. 558,717

ALFRED 0. TATE, OF TORONTO, ONTARIO, CANADA.

ART OF WATERPROOFING FIBROUS ,MATERIALS,

No Drawing.

To all whom it may concern:

Be it known that I, ALFRED O. TATE, a subject of the King of Great Britain, residing in Toronto, Ontario, Dominion of Canada, have made a new and useful-Invention in the Art of 'Waterproofing Fibrous Materials, of which the following is a specification.

My invention is directed particularly to an improved method or process of water? proofing fibrous articles, such as woven, knit, or fibrous cloths, for clothing materials, sails of vessels, tents, tarpaulins, etc., and it has for its objects, first, to effect such a result by overcoming in fabrics practically all tendency to capillary attraction in the fibers thereof; second, to effect a coating on the fibers .of either or both surfaces of the material which shall prevent the penetration of moisture; third, to produce a ventilated water-proof product which has an especial utility in connection with clothing.

Prior to my invention attempts have been made to water-proof materials of the character referred to by saturating the same in an electrolytic solution containing a soluble metallic salt, such as sulfate of aluminum, and afterward placing it under a certain degree of pressure between two electrodes and passing a current of electricity therethrough. Processes of this general nature are disclosed in U. S. patents to Henry and 558,718 of April 21st, 1896; and to Jean T. Van Gestel,

' Nos. 653,715 and 653,716, July 17th,1900.

It is assumed in the before-mentioned patcuts that the water-proofing of the material is effected by the actual transmission of the insoluble matter in the electrolyte into the inner surfaces of the fibers and is deposited thereon by virtue of the electrolytic action, but I have ascertained after a longseries of experiments that such is not the case andthat at best only a slight coating of the insoluble substance is deposited upon one face of' the material and that face which, when exposed under the influence of the current in an electrolytic bath, is adjacent to the cathode. I have also ascertained that fabrics as thus treated, after usage a short time, lose practically all of their water-proofing capacity, owing to the fact that the outer or water-proofed surface Specification of Letters Patent.

opposite direction to the 'I also observed that suifuslon in this direcbeing subjected to' Patented Sept. 14, 1909.

Application filed. June 1, 1907. Serial No. 376,841.

will become cracked or disrupted and the deposited substance in the inner surfacewhich substance is soluble-will leach or drain out in use.

Before proceeding with the tests proved to me conclusively these facts I deemed it important to determine definitely the nature of the forceor energy which causes a fabric to become saturated with a liquid when submerged therein, or placed in contact therewith. On laying a piece of silk or similar fabric upon the surface of a basin of water I observed that it instantly became suffused and that the water entered the same by ascending ther through directly in the force of gravity.

tion was quite as rapid as suffusion in the opposite direction or in the lines of the force of gravity. This clearly proved to me that such action was due to another force or form of energy than gravity and none other than what is known as capillary attraction, most commonly made use of in connection with lamp wicks, blotting paper, and similar absorptive agencies. For the purpose of determining whether gravity performed any portion of this suffusion I procured a piece of cloth in which the meshes or pores were clearly visible when held before the light and treated it in accordance with my novel process which I will hereinafter describe, the meshes after treatment being as clearly open and visible as before. I made a bag of this treated material, as hereinafter described, filled it with water, and found that none of the water would pass through the open meshes, the reason being that the weight of such water in the minutely subdivided form in which it would have to enter these meshes was insufficient to displace the air columns with which the meshes were already filled, or in other words, the water was prevented from entering these meshes or pores by atmospheric pressure, just as water is prevented from leaving a small tube when the weight of the column ofwater is less than the atmospheric pressure upon the superficial area at the lower end of the tube. This experiment conclusively demonstrated to me the fact that all ordinary fabrics in contact with liquids become suffused by reason of capilwhich or material of a fibrous or lary action and was not due to passage thereof through the meshes, and showed further, in my mind, that if this capillary action could be suspended or overcome the fabric would be practically water-proofed.

For the purpose-of disclosing my invention more fully I will assume that any fabric orous nature which has the power of capil ary action is possessed of two systems of capillaries ;(1) an outside or surface system which may be brought directly into contact with the electrodes of an electrolytic bathas I have ascertained that'chemic'al changes in the treatment of such materials can only occur on the faces of such electrodes and not in the electrolytic solution, as is maintained by the inventors in the before-mentioned patents. (2) An inner system in which the original condition of the solution employed undergoes no chemical change through electrolytic action. i

For the purpose of making the several tests, both as to the processes dlsclosed in the before-mentioned process, I organized the following apparams-(1) An'anode composed of a 5: inch copper plate 14''x 14: sq

so as to lnsure an even distribution of the current. (2) A cathode consisting of a 5 inch aluminum plate about 8 8", provided with like wiring and binding post connections for the purpose of insurm distribution of the current. voltmeter. (4) A Weston ammeter. .(5) A variable resistance to regulate the current flow. 6) An electric generator having suf-' ficient current generating capacity to make the tests.

. peres of soluble Following the processes described in the before-mentloned patents, I pre ared a solution consistin of 4 oz. of sul ate of aluminum dissolved in a half gallon of distilled water. The fabrics to be treated were then immersed in this solution and placed between. the before-mentioned electrodes and current applied. After a long series of tests I ascertained that for silk fabrics the best results were obtained with a 'current strength of 45 ampere seconds, or 10 amapplied for 41} seconds. The chemical reaction in this case-which fproduces the abric is due to the preclpitation at the cathode of hydroxid of aluminum'which fills the outside or surface system of capillaries where such surface rests against the face of the electrode, and this substance is insoluble in water.

The inner system of capillaries is filled with the'solution alone in itsoriginahstate and when the fabric is dried there is formed therein an extremely thin de osit 'or scale patents and as to my novel I uare, interconnected at its. under side by wires and a series of; binding posts distributed at several points matter which is rapldly destroyed v by absorption, if water be introduced through the meshes or by pressure.

For the purpose of further disclosing the fact that processes of this nature are based upon a misconception of facts I covered the cop er anode with two thicknesses of pores of the fabric I obtained with sulfate ofaluminum were very unsatisfactory. The water-proof efthe fabrics tested fected. Therefore, 4 oz. of sulfate of aluminum and 'otassium (alum) dissolved in a gallon o distilled water. This produced marked improvement, but, nevertheless, I ascertained that from a dozensamples of silk fabric thus treated only two were water-proofed and as in the first case the results were easily destroyed when the material was subjected to mechanical pressure. The reason for this is apparent. The oxid which fills the being in the nature of an exceedingly thin film ossessing no marked adhesive qualities.

en water is forced through the meshes orpores of a fabric, after the above treatment, the outside film is ruptured and thev inside capillaries containing the dried" soluble matter are leached or drained out. This.

salts of any of the other metals. described in the before-mentioned patents. After havace under practically all ared a solution con ate of soda (whiteing'made these tests from which I'arriv'ed at the above-named conclusions, itoccurredto me that the correctness of my deductions filling the inner;

cotton c oth soaked in the before-mentioned demonstrated by me by a very exhaustive series of tests. Theresults which as fects were easily broken down and most of were only partially af- I prepared a solution of surface system of capillaries may be described as. a like even (3 A Weston same'result will follow upon the use of the v I sealin substance, would-remain 1 To this end I devised boiling in it I process, a

covering the anode were then immersed in this solution and laid smoothly in place. The fabric was also immersed in the same solution and spread on top of said buffers. A quantity of the alum solution, hereinbcfore referred to, sufficientto cover it was then poured over .the surface of the fabric which was immediately inclosed by the aluminum cathode plate and a current.

strength of 4:5 ampere seconds applied. Under this condition the action of electrolysis causes the palmic acid of the first solution (palmate of soda) to combine at the cathode with the aluminum contained in the second solution (alum) with the result, concerning the fabric, that the outside or surface capillaries are filled with insoluble palmate of aluminum, while the inside capillaries retain a filling of semi-insoluble matter that cannot be removed under ordinary conditions that may reasonably be anticipated. This inner filling constitutes a medium which prevents or overcomes capillary action. I ascertained that silk samples thus treated might be washed or scrubbed with tar soap, after such watcr-prooting treatment and after the material had dried, without in any way impairing the waterproofing efficiency. l I

Although I have described the preferred material for use in connection with the practice of my method or process as being palmate of soda (white castile soap) and alum, I do not limit the same to such substances; nor to the proportions of the salts which constitute the aluminum base.

have been with a combination of 75 parts aluminum salts and 25 parts potassium salts, using ordinary white cast-ile soap as before. The essential principles of my invention lie in permeating or impregnating the interior portions of the fabric or material to be treated with a medium which tends to overcome or preyent capillaryaction and afterward coating the capillary surface only of either one or both sides of the fabric with a water-proof deposit preferably electrolytic-and derived from a metallic base, and my claims are to be construed as of the most generic nature in these respects. Nor do I limit myself to the use of electrodes of copper and aluminum, as obviously various types of electrodes may be utilized and in fact I prefer in some cases to use electrodes of carbon, preferably that type of carbon known as'the Acheson graphite carbon manufactured in Niagara Falls, N. Y.

I make no claim hereinafter to the product which regs'ults from my novel method or this" constitutes the subject matter 'ifa s rparate application filed by me on fibers with a saponaceous substance,

Infact the best results which I have obtained the 25th day of February, 1908 bearing Serial No. 417,689. I

Having thus describedmy invention what I claim and desire to secure by Letters Patent of the United States is 1. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior fibers with a substance which renders the same practically non-capillary, and after- 'ard electrolytically effecting the coating of one or both surfaces of such material with a water-proofing substance.

:2. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior fibers with a substance which. renders the same practically non-capillary, and after ward electrolytically effecting the deposit of a water-proofing coating, in the nature of a hydroxid, on one or both surfaces of the material.

3. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior and afterward electrolytically coating one or both surfaces of the material with a waterproofing substance.

4. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior fibers with asa]')()naccous substance and afterward depositing palmate of aluminum upon one or both surfaces of the material.

5. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior fibers with a saponaceous substance. and afterward electrolytically depositing palmate of aluminum upon one or both surfaces of the material.

(3. The described method or process of water-proofing fibrous materials, consisting in permeating or impregnating the interior fibers with palmate ofsod'a and afterward coating one or both surfaces of the material with palmate of aluminum.

T. The described method or process of water-proofing fibrous n'laterials, consisting in permeating or impregnating the interior fibers with palmate of soda and afterward electrolytically coating one or both surfaces of the material with palmate of aluminum.

In testimony whereof I have signed my name to" this specification in the presence of two subscribing witnesses.

ALFRED O. TATE.

\Vit-nesses C. J. K-m'rnnn, W. JraN OConnoa. 

